Set up a participant survey

[Daniel-Mietchen]

• should be simple, slick, useful
• perhaps just use a GitHub issue that people respond to

[Daniel-Mietchen]

Here's the follow-up questionnaire for brainhack Cambridge:
https://docs.google.com/forms/d/e/1FAIpQLSdJFVxmjQHFnosooEHjDG4_Wp3UNsDXOfzPpoN2I4aqeKbGsQ/viewform?c=0&w=1 .